Overview2660021169012 Rev. A 2017-12 CIRRUS HD-OCT User Manual9-6• Sub-RPE: The OCT Analysis uses a predefined Sub-RPE slab. The Sub-RPE slab uses aPixel option that can calculate the pixel values or maximum pixel values. The Sub-RPEpreset default Project type MAX project method is defined as follows:Top: RPE + 29 μmBottom: RPE + 49 μmNOTE: This preset is not available for ONH Angiography.• RPE RPE-Fit: The RPE to RPE-Fit preset uses the summation of pixel values as thedefault. The RPE RPE-Fit preset covers the region between the RPE to RPE-Fit layers.NOTE: This preset is not available for ONH Angiography.• Whole Eye: This preset is intended to illustrate vasculature of the whole posteriorsegment that was scanned. There are no top or bottom reference layers.• RPC: The Radial Peripapillary Capillary (RPC) preset performs a vessel perfusionmeasurement analysis for the RPC layer. The RPE preset is defined as follows:Top: ILMBottom: RNFLNOTE: This preset is only available for ONH Angiography.These slab / en face definitions should be considered reasonable starting points, especiallyfor normal eyes, but the inner and outer boundaries can be offset by grabbing magentalines and shifting them in the B-scans. Furthermore, the slabs will not appropriatelyillustrate the vasculature of interest if the segmentation has failed. In this case, a layersegmentation editor is available as a licensed feature for the user to edit the ILM andRPE boundaries.As with the En Face analysis, you may create your own custom presets as follows:• Create Global Custom: Specify a region of interest that, once created, is available foranalysis for all scans.• Create Scan Custom: Specify a region of interest that, once created, is available foranalysis for a specific scan.The custom slabs uses a Pixel option that can calculate the pixel values or maximumpixel values. These two custom options are described further in "Create GlobalCustom" on page 8-4 and "Create Scan Custom" on page 8-4 respectively.
